docs: def do_serialize(self, line):
          """Serialize an entity into an RDF flavour"""
          opts = self.SERIALIZE_OPTS
  
          if not self.current:
              self._help_noontology()
              return
  
          line = line.split()
          g = self.current['graph']
  
          if not line:
              line = ['turtle']
  
          if line[0] not in opts:
              self.help_serialize()
              return
  
          elif self.currentEntity:
              self.currentEntity['object'].printSerialize(line[0])
  
          else:
              self._print(g.rdf_source(format=line[0]))